Question

In hurdle races, what is the major source of energy to leg muscle?
A. Preformed ATP
B. Oxidative metabolism
C. Pyruvate and lactate
D. Glycolysis

Answer 1

Hint: Our muscles convert energy into energy of motion. They use the stored energy of food we eat and convert that to heat and energy of motion (kinetic energy). We want energy to enable growth and repair of tissues, to keep up temperature and to fuel physical activity. Energy comes from foods rich in carbohydrate, protein and fat.

Complete Answer:
Origins of the Energy for muscular contraction: The source of energy that's accustomed to power the movement of contraction in working muscles is ATP (ATP) – the body’s biochemical thanks to store and transport energy. However, ATP isn't stored to a good extent in cells. So once shortening starts, the making of more ATP must start quickly. Since ATP is so important, the muscle cells have several other ways to form it. These systems work together in phases. The three biochemical systems for producing ATP are, in order:
1. Using phosphocreatine
2. Using glycogen
3. Aerobic respiration

Creatine Phosphate (with oxygen): All muscle cells have a bit ATP within them that they will use immediately – but barely enough to last for about 3 seconds! So all muscle cells contain a high-energy compound called organic compound which is weakened to create more ATP quickly. creatine phosphoric acid can supply the energy needs of a working muscle at an awfully high rate, but just for about 8–10 seconds.

Glycogen (without oxygen): Fortunately, muscles even have large stores of a carbohydrate, called glycogen, which may be accustomed to make ATP from glucose. But this takes about 12 chemical reactions so it supplies energy more slowly than from phosphocreatine. It’s still pretty rapid, though, and can produce enough energy to last about 90 seconds. Oxygen isn't needed – this is often great, because it takes the center and lungs a while to urge increased oxygen supply to the muscles. A by-product of creating ATP without using oxygen is carboxylic acid.

Aerobic Respiration (with oxygen): Within two minutes of exercise, the body starts to produce working muscles with oxygen. When oxygen is present, aerobic respiration can occur to interrupt down the glucose for ATP. This glucose can come from several places:
• Remaining glucose supply within the muscle cells
• Glucose from food within the intestine
• Glycogen within the liver
• Fat reserves within the muscles
• In extreme cases (like starvation), the body’s protein.

Aerobic respiration takes even more chemical reactions to supply ATP than either of the above two systems. It's the slowest of all three systems – but it can supply ATP for several hours or longer, as long because the supply of fuel lasts.
Therefore, the correct answer is a, preformed ATP

Note: Different sorts of exercise use different systems to supply ATP. A sprinter is getting ATP during a very different time thanks to a runner.
• Using creatine phosphate – this may be the foremost system used for brief bursts (weightlifters or short distance sprinters) because it's fast but lasts for less than 8–10 seconds.
• Using glycogen (no oxygen) – This lasts for 1.3–1.6 minutes, so it might be the system utilized in events just like the 100 meter swim or the 200 m or 400 m run.
• Using aerobic respiration – This lasts for a limitless time, so it’s the system utilized in endurance events like marathon running, rowing, distance skating etc.